The field of the present disclosure relates generally to hydrogen embrittlement, and more specifically, to methods and systems for testing for potential hydrogen embrittlement.
Hydrogen embrittlement refers to a process that causes a metal or metal alloy, such as steel, to become brittle and susceptible to fracture when exposed to a quantity of hydrogen and subjected to a tensile load. As used herein, the term “metal” may refer to a single metal or a metal alloy. Hydrogen embrittlement generally occurs when hydrogen atoms diffuse through the crystalline structure (i.e., matrix) of a metal resulting in an increased pressure within the metal matrix. The increased pressure can adversely affect characteristics of metal such as ductility and tensile strength. At least some known sources of hydrogen atoms are electroplating solutions, pickling solutions, phosphating solutions, paint-stripping solutions, cleaning solutions, and the like.
In at least some known electrodeposition processes, a metal substrate cathode and a plating material anode are submerged in a plating solution. Electric current is applied to the anode and cathode to deposit a layer of plating material on the surface of the metal substrate via the plating solution. After a desired amount of plating material has been deposited on the metal substrate, the substrate may then be heated to facilitate removing hydrogen trapped in the steel substrate beneath the plating material. Metal substrates also generally have organic surface contaminants, which if not properly cleaned prior to plating, may contaminate the plating solution. As such, prolonged use of the plating solution may affect the quality of the plated sample due to the contaminants. For example, an increased contaminant concentration in the plating solution may decrease the porosity of the plating layer, thereby limiting the amount of hydrogen removed from plated metals during the post-deposition heating process, which is commonly referred to as Hydrogen Embrittlement Relief Baking.
One known method of determining the porosity level of plating solution involves performing a series of stress tests on samples plated using a plating solution. In one known stress test, plated samples fabricated from a rigid metal substrate, such as AISI 4340 steel, are subjected to tensile stress at 75 percent of their respective ultimate failure load for a predetermined duration. The plating solution is determined to be contaminated if the plated sample breaks before the end of the predetermined duration. However, these known test methods are generally time-consuming, can take up to 200 hours to complete, and thus make it difficult to determine the contamination level of plating solution in real-time.